1. Field of the Invention
The present invention relates to a process for producing a liquid jet recording head for ejecting a recording liquid as a liquid droplet by using an ink jet recording system.
2. Description of the Prior Art
A liquid jet recording head applied to an ink jet recording system (a liquid jet recording system) usually has a fine liquid discharging port (hereinafter referred to as orifice), a liquid flow path and a liquid discharge energy generator arranged along the liquid flow path. Heretofore, such a liquid jet recording head has been manufactured, for example, by forming fine grooves on a glass plate, a metal plate or the like by cutting or etching, and joining the grooved plate to another appropriate plate to form the liquid flow paths.
However, in the liquid jet recording head manufactured by the above conventional method, roughness in the liquid flow path inner wall thus cut is too high or the liquid flow path has a strain due to a difference in etching rate. Accordingly, it is difficult to form a liquid path of a constant flow path resistance and the liquid discharge characteristics of the liquid jet recording head thus manufactured are not uniform.
During the cutting step, the plate may be easily cracked or broken. Thus manufacturing yield is low. When the etching processing is carried out, the number of the manufacturing steps increases and the manufacturing cost increases. Further, the above-mentioned conventional methods have the following common defects.
(1) An overlaying plate for a driving element such as a piezoelectric element, an electro-thermal transducer and the like generating discharge energy for discharging recording liquid droplet is difficult to set accurately on a grooved plate in which the liquid flow path is formed.
(2) It is difficult to utilize when producing large quantities.
In the general cases, the liquid jet recording head is always in contact with the recording liquid when in use. The above recording liquid is generally an ink liquid mainly composed of water which is not neutral in many cases or an ink liquid mainly composed of an organic solvent. Therefore, it is desired to use a head-constituting material of the liquid jet recording head which does not cause a lowering of the strength by the influence of the recording liquid and to use a recording liquid in which a harmful ingredient causing deterioration of the recording liquid is not contained. However, in the conventional methods, a material answering the purpose could be not always selected due to the restriction of the processing method, etc.
Further, U.S. Pat. No. 4,412,224 discloses a process for producing a liquid jet recording head as described below. The following steps are successively carried out: (1) forming a resist pattern constituting the liquid flow path on the substrate using a negative type photoresist, (2) forming the side wall part of the liquid flow path on the portion, on which the above resist pattern is not provided, by electroplating, (3) removing the resist pattern from the substrate, and (4) providing the ceiling plate.
However, for removing the above resist pattern from the substrate (the step of (3)), exfoliation of the pattern has been carried out only by swelling the resist pattern in a liquid since the resist pattern composed of the negative type photoresist is not dissolved in a liquid. In this case, there is a drawback that the above pattern adheres partly, as the remains, to the substrate and the liquid flow path wall to cause lowering of the size accuracy of the liquid path.